Safety attachment for orthodontic wires and pliers to apply attachment

ABSTRACT

A safety attachment for application to orthodontic wire in the mouth of a patient comprises a safe-end portion to be crimped onto the orthodontic wire, which once in place on the wire has no sharp edges. The safety attachment comprises upper and lower portions secured to each other by a hinge. One or both of the inner surfaces of the attachment may be textured to improve grip on the wire. The safety attachment may include means for retention by application pliers. Pliers designed for application of a safety attachment have upper and lower beaks, wherein the upper beak includes means to crimp the safe-end portion onto an orthodontic wire and the lower beak includes means to retain the safety attachment prior to applying the safe-end portion to the wire and after application release the safe-end portion leaving it in place on the wire in the patient&#39;s mouth.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/GB2008/000018, filed Jan. 4, 2008, which claims priority from GBPatent Application No. 0700495.5, filed Jan. 11, 2007. The disclosuresof both applications are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The invention relates to a safety attachment for orthodontic wires andpliers to apply the safety attachment.

Orthodontic braces consist of brackets that are affixed to teeth, andorthodontic wires, which will simply be referred to hereinafter as wiresfor the sake of brevity that attach to those brackets to deliver acontrolled force to move and guide the teeth, such that they come intothe desired alignment. At the beginning of treatment, the wires used areof small diameter, as small as 0.3 mm or less, and are very flexible. Astreatment progresses the wires used may be of larger diameter and thusbe less flexible.

Using the small diameter wires at the start of treatment in particularposes three problems, as follows.

1. The flexibility of the wires allows them to distort and pull out ofthe bracket on the last tooth in the dental arch usually a molar, with atube type of orthodontic bracket.

2. When placing the wires, excess wire is clipped off from behind thelast most tooth. Pliers designed to cut and hold the excised wirefragment, so that the fragment can safely be removed from the mouth, canfail to adequately hold very thin wires such that the fragment of wireis dropped in the back of the patient's mouth and it is then difficultto locate and recover.3. As teeth align during the orthodontic treatment, less length of wireis needed and excess wire protrudes at the back behind the last mosttooth. This can occur between appointments with the orthodontist and cancause ulceration to the cheeks of the patient, even if the end of thewire is curved into a loop. In addition, it is difficult to access thewire at the back of the mouth in order to adequately turn it into aloop. Furthermore, modern flexible-alloy wires resist deformation and donot readily accept the imposition of a shape-change, making it difficultto obtain adequate curvature to create a loop that makes the wire safe.

All three problems pose a health risk to orthodontic patients andgenerate emergency visits, which increase the workload of theorthodontist. A solution to these problems is therefore highlydesirable.

It is an object of the present invention to provide a safety attachmentfor orthodontic wires and pliers to apply the attachment, which mitigatethe above described problems.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided asafety attachment specifically designed for application to orthodonticwire in the mouth of a patient, the safety attachment comprising asafe-end portion to be crimped onto the orthodontic wire, which once inplace on the wire has no sharp edges characterized in that it comprisesupper and lower portions secured to each other by a hinge.

Further features of the safety attachment are set out in theaccompanying claims.

According to a second aspect of the invention there are provided pliersspecifically designed for application of a safety attachment accordingto the first aspect of the invention, the pliers having upper and lowerbeaks, wherein the upper beak includes means to crimp the safe-end ontoan orthodontic wire and the lower beak includes means to retain thesafety attachment prior to applying the safe-end to the wire and afterapplication release the safe-end leaving it in place on the wire in thepatient's mouth.

Further features of the pliers are set out in the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the safety attachment and the pliers will now bedescribed, by way of example only, with reference to the accompanyingFigures in which:

FIG. 1( a) schematically illustrates a side view of the prior artproblem to be solved;

FIG. 1( b) schematically illustrates a back view of the prior artproblem to be solved;

FIG. 2( a) schematically illustrates a top view of a first embodiment ofa safety attachment according to the invention;

FIG. 2( b) schematically illustrates an end view of the first embodimentof the safety attachment of FIG. 2( a);

FIG. 2( c) schematically illustrates a side view of the first embodimentof the safety attachment of FIG. 2( a);

FIG. 3( a) schematically illustrates side view of beaks of pliers usedto apply the first embodiment of the safety attachment of FIG. 2;

FIG. 3( b) schematically illustrates the lower face of the upper beak ofthe pliers of FIG. 3( a);

FIG. 3( c) schematically illustrates the upper face of the lower beak ofthe pliers of the pliers of FIG. 3( a);

FIG. 4( a) schematically illustrates a side view of the attachmentaccording to the invention in place on the wire after application usingthe pliers;

FIG. 4( b) schematically illustrates an end view of the attachment ofFIG. 4( a);

FIG. 5( a) schematically illustrates a top view of a second embodimentof a safety attachment according to the invention;

FIG. 5( b) schematically illustrates a side view of the secondembodiment of the safety attachment of FIG. 5( a);

FIG. 6( a) schematically illustrates a side view of beaks of pliers usedto apply the second embodiment of the safety attachment of FIG. 5( a),in side view closing around the attachment;

FIG. 6( b) schematically illustrates the lower face of the upper beak ofthe pliers of FIG. 6( a);

FIG. 6( c) schematically illustrates the upper face of the lower beak ofthe pliers of FIG. 6( a);

FIG. 7( a) schematically illustrates a bottom view of a third embodimentof a safety attachment according to the invention;

FIG. 7( b) schematically illustrates a cross section of the thirdembodiment of the safety attachment taken along line Y-Y of FIG. 7( a);

FIG. 7( c) schematically illustrates a cross section of the thirdembodiment of the safety attachment taken along line X-X of Figure (a);

FIG. 8( a) schematically illustrates an end view of beaks of pliers usedto apply the third embodiment of the safety attachment of FIGS. 7( a)through 7(c);

FIG. 8( b) schematically illustrates a side view of the beaks of thepliers of FIG. 8( a);

FIG. 8( c) schematically illustrates the inner face of the upper beak ofthe pliers of FIG. 8( a);

FIG. 8( d) schematically illustrates the inner face of the lower beak ofthe pliers of FIG. 8( a);

FIG. 9 schematically illustrates the third embodiment of a safetyattachment according to the invention in place on a wire afterapplication using the pliers;

FIG. 10( a) schematically illustrates a side view of a fourth embodimentof a safety attachment according to the invention;

FIG. 10( b) schematically illustrates a top view of the fourthembodiment of the safety attachment of FIG. 10( a);

FIG. 11( a) schematically illustrates a front view of a fifth embodimentof a safety attachment;

FIG. 11( b) schematically illustrates a top view of the fifth embodimentof the safety attachment of FIG. 11( a);

FIG. 12( a) schematically illustrates an end view of beaks of pliers forapplication of the fourth of fifth embodiments;

FIG. 12( b) schematically illustrates a side view of the beaks of pliersof FIG. 12( a);

FIG. 13 schematically illustrates beaks of pliers for cutting theorthodontic wire to the length required for application of one of thesafety attachments;

FIG. 14 schematically illustrates beaks of pliers for safe removal ofone of the safety attachments,

FIG. 15( a) schematically illustrates a top view of a sixth embodimentof a safety attachment according to the invention;

FIG. 15( b) schematically illustrates a bottom view of the sixthembodiment of the safety attachment of FIG. 15( a);

FIG. 15( c) schematically illustrates an end view of the sixthembodiment of a safety attachment of FIG. 15( a); and

FIG. 15( d) schematically illustrates a back view of the sixthembodiment of a safety attachment of FIG. 15( a).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring first to FIGS. 1( a) and 1(b) an orthodontic fixed applianceincludes a bracket, called a tube 1 that is affixed to a molar tooth 2.Through this tube 1 passes a wire 3, the protruding portion of which, inthe prior art, is then bent at an angle to create a turned end 4 as itemerges from the tube behind the molar tooth. The bending of the wire 3to create the turned end 4 is designed to do two things. The first is tohelp prevent the wire 3 from being pulled back forwards through the tube1 accidentally. The second is that it presents a curved profile of wire3 rather than a cut and sharp end, which might cause trauma to thecheeks of the patient. However, creating an adequate angle to achieve asatisfactory result, especially in small diameter flexible-alloy wires,is difficult.

Often the wire 3 still pulls through the tube 1 and sometimes the turnedend 4 unbends between appointments so that a sharp end is produced.

Referring now to FIGS. 2( a) through 2(c), a first embodiment of theinvention will be described. In its initial form a safety attachment Aconsists of four portions: a first portion is a safe-end portion 6,which in use is closed around the wire 3 and is left on the wire 3 inthe patient's mouth as a safe-end; a second portion comprises aconnecting isthmus 7; a third portion is a wire-retaining portion 8,which in use is closed around the excised wire fragment, maintaininghold of it so that it can be removed with the pliers, and a fourthportion is a retaining lug 9, that is retained in the jaws of pliers aswill become clear so that the excised fragment can be safely removedfrom the patient's mouth without danger of being dropped.

When viewed from the end as in FIG. 2( b), the safety attachment Aresembles a split-shot weight as used in angling, with upper and lower,portions 12 and 13 that are connected on one side only by a thin area ofmetal which acts as a hinge 10. The internal faces 11 a, 11 b of theupper and lower portions 12 and 13 are serrated to increase grip on thewire 3. When viewed from the side as in FIG. 2( c), the division betweenthe upper portion 12 and the lower portion 13 can be seen. The retaininglug 9 and connecting isthmus 7 are positioned level with the upper face11 b of the lower portion 13.

Referring now to FIGS. 3( a) through 3(c), the safety attachment A isapplied to the wire 3 using specially designed pliers the upper beak 14and lower beak 18 of which are shown schematically. The beaks 14, 18 areformed integrally with or secured to arms (not shown) of pliers inconventional manner to provide the entire tool. The upper beak 14carries three blades 15, 16 and 17. The first blade 15 is to crimp thewire-retaining portion 8 so that it grips the wire 3. The second blade16 is to cut through the connecting isthmus 7. The third blade 17 is tocrimp the safe-end portion 6 so that it grips the wire 3. The lower beak18 carries one blade 19 to fit under the connecting isthmus 7 and whichis aligned with the second blade 16 of the upper beak 14, this ensuresthat when the pliers are closed there is a clean cut of both the isthmus7 and the wire 3. The crimping blades 15 and 17 may be multiple bladesand/or broad flat ended blades in order to provide the best crimpingaction without risk of cutting through the portions 6 and 8 of thesafety attachment A.

The lower beak 18 also includes an upstand 20 within which is provided arecess 20 a, with an opening 20 b facing the blade 19. The recess 20 ais shaped for receipt of the retaining lug 9. The lug 9 and recess 20 acooperate to prevent the safety attachment A being accidentallydislodged during use in the patient's mouth, and to ensure that the wireretaining portion 8 and wire fragment are safely removed from thepatient's mouth.

A bore 21 runs vertically through the upstand 20 from the outer face ofthe lower beak 18 and the recess 20 a. The bore 21 is provided to allowinsertion of a dental probe or similar instrument to remove the lug 9and retained wire fragment following attachment of the safe-end 6 to thewire 3 in the patient's mouth. The lug 9 and retained wire fragment canthus be dropped directly into a secure sharps container in accordancewith health and safety procedures.

Referring now to FIGS. 4( a) and 4(b) the end result of use of thesafety attachment is illustrated, showing the safe-end 6 in place on theend of the wire 3. The safe-end 6 is shaped to have no sharp edges, thatis to be spherical or ovoid or the like, in order to minimize thechances that it can cause any damage to the cheeks of a patient. Thesafety attachment can be used for all wires to apply a safe-end 6 as ananti-pull-through device and so as to ensure patients are protected fromwire-pokes.

Referring now to FIGS. 5( a) and 5(b) a second embodiment of a safetyattachment B according to the invention is illustrated with parts commonto the first embodiment being like referenced, but with the addition ofa “′”. The safety attachment B is for use where there is no requirementto remove any of the wire 3, that is the wire 3 is already of thecorrect length, and thus no wire fragment needs to be retained andremoved from the patient's mouth. Thus the safety attachment B simplycomprises a safe-end 6′ and a retaining lug 9′ connected by an isthmus7′, these parts being substantially as previously described withreference to safety attachment A.

Referring now to FIGS. 6( a) through 6(c), upper beak 22 and lower beak25 of pliers designed for application of the safety attachment B areillustrated schematically. The upper beak 22 carries only two blades 23and 24. The first blade 23 is designed to cut through the isthmus T butnot through the wire 3. The first blade 23 does not extend the fullwidth of the upper beak 22, so as to avoid impinging on the wire 3. Thesecond blade 24, which may be a multiple blade and/or which may be aflat ended broad blade, is designed to crimp the safe-end portion 6 ontothe wire 3 so that it is safely retained.

As with the pliers to apply the first embodiment of the safetyattachment A, there is a recess 20 a′ in the lower beak 25 to receivethe retaining lug 9′ and there is a bore 21′ to accept a dental probe orsimilar instrument to facilitate removal of the retaining lug 9′ fromthe pliers after use.

Referring now to FIGS. 7( a) through 7(c), a third embodiment of asafety attachment C according to the invention is shown schematicallywith parts common to the first embodiment being like referenced, butwith the addition of a“″”. The safety attachment C comprises a safe-end6″, which has an indentation 26 in its lower surface.

Referring now to FIGS. 8( a) through 8(d), upper beak 27 and lower beak29 of pliers designed for application of safety attachment C areillustrated schematically. The upper beak 27 is provided with two blades28 designed to crimp the safe-end 6″ onto the wire 3. The lower beak 29carries a protrusion 30, running parallel to and between the blades 28on the upper beak 27. Retention of the safety attachment C on the pliersis provided by friction between the protrusion 30 and the indentation26, because they are an interference fit. Preferably the interferencefit is only provided in direction Y-Y or direction X-X and not bothdirections. This is to ensure that there is sufficient freedom betweenthe pliers and the safe-end 6″ after application to the wire 3 to allowrelease of the pliers from the safe-end 6″.

Referring now to FIG. 9, the shape of the safe-end 6″ after applicationto the wire 3 is illustrated. As can be seen the use of two blades 28with a protrusion 30 there between has deformed both the safe-end 6″ andthe wire 3. This deformation of the wire 3 further assists retention ofthe safe-end 6″ on the wire 3 and makes pull through even less likely tooccur.

Referring now to FIGS. 10( a) and 10(b), a fourth embodiment of a safetyattachment D according to the invention is shown schematically. Thesafety attachment D comprises a safe-end 6′″, but being a simplifiedversion of safety attachment C does not have an indentation in its lowersurface.

Referring to FIGS. 11( a) and 11(b), a fifth embodiment of a safetyattachment E according to the invention is shown schematically. Thesafety attachment E comprises a safe-end 6″″, which has a groove 38running along its upper surface.

Referring to FIGS. 15( a) through 15(d), a sixth embodiment of a safetyattachment F according to the invention is shown schematically. Thesafety attachment F comprises a safe-end 6′″″, which has a groove 38running along its upper surface and a ridge 40 extending along its lowersurface, the groove 38 and the ridge 40 running substantially parallelto each other and substantially perpendicular to the hinge 10 joiningthe upper and lower portions 12, 13. The ridge 40 is provided to assistin retaining the safety attachment F in the beaks of pliers when it isbeing fitted in a patient's mouth.

Referring to FIG. 12, upper beak 39 and lower beak 41 of pliers designedfor application of safety attachment D, E or F are illustratedschematically. The upper beak 39 has a blade 43 on its midline designedto crimp the safety attachment onto an orthodontic wire 3, but also toengage in the groove 38 when being used to fit safety attachment E or F.The lower beak 41 is shaped, with extensions 42 and a central recess 44,so as to accept safety attachment D, E or F and support it duringinsertion into the mouth, whilst also permitting deformation of thesafety attachment D, E or F during crimping.

The clinical procedures for placing a safety attachment A, B, C, D, E orF are as follows.

The chosen safety attachment is inserted into the lower beak of therespective pliers, and retained as described above. The upper beak ofthe pliers is closed gently onto the safety attachment to further secureit. It is then possible to safely transfer the safety attachment, in thepliers, into the mouth of the patient without risk of the safetyattachment being dislodged or dropped within the oral cavity even if thepliers are inverted during insertion. This permits safe use in all fourcorners of the mouth.

The pliers are constructed with an angle of between 80° and 145° betweenthe beaks and the handles (not shown) so as to facilitate access to thewire protruding from the tube on the last most tooth. The safetyattachment, having its hinge part 10 to the hinge of the pliers (notshown) and offering its open aspect to the outside of the pliers, isplaced over the wire until the wire is hard up to the hinge part 10 ofthe safety attachment. The handles of the pliers are then squeezedtogether firmly. This action crimps the safety attachment onto the wireand, for attachments A and B also clips through the retaining lug 9 or9′ so as to allow the pliers to be removed, leaving the safe end 6, 6′,6″, 6′″, 6″″ or 6′″″ on the wire.

Referring now to FIG. 13, beaks of pliers designed to clip theprotruding portion of the wire 3 to a specific length such that, when aselected safety attachment, as previously described, is applied thesharp end of the wire will be safely enclosed within the safe endthereof. The pliers have upper and lower beaks 31, 31′, which each carryfirst blades 32 and second blades 33, which are opposed to thecorresponding blades on the other beak 31, 31′. The first blades 32 arelonger than the second blades 33, such that the first blades 32 severthe wire whilst the second blades 33 retain the excised fragment forsafe removal from the patient's mouth. Faces 31 a of the beaks 31, 31′are placed against the rear of the last most tooth during the cuttingprocess and plain section 34 of the beaks 31, 31′ acts as a spacer toensure that the wire 3 is cut so as to leave the correct length ofprotruding portion behind the last most tooth.

Referring now to FIG. 14, beaks of pliers, designed for removal of thesafety attachment when it is no longer required and for its safe removalfrom the mouth, are illustrated. Upper and lower beaks 35, 35′ eachinclude a blade 36 for cutting the wire 3 immediately behind the lastmost tooth, and a recess 37 for receipt of the safe end being removed.As the blades 36 cut the wire, the remainder of each beak 35, 35′receives and grips the safe end with the previously protruding portionof the wire embedded in it, retaining it for safe removal from thepatient's mouth.

When used in this specification and claims, the terms “comprises” and“comprising” and variations thereof mean that the specified features,steps or integers are included. The terms are not to be interpreted toexclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the followingclaims, or the accompanying drawings, expressed in their specific formsor in terms of a means for performing the disclosed function, or amethod or process for attaining the disclosed result, as appropriate,may, separately, or in any combination of such features, be utilized forrealizing the invention in diverse forms thereof.

1. A combination, comprising: safety attachment comprising: a safe-endportion comprising an upper portion having a lower face, a lower portionhaving an upper face, and a hinge connecting the upper and lowerportions to permit the lower and upper faces to be closed together, thesafe-end portion having no sharp edges when lower and upper faces areclosed together; a retaining lug extending from the lower portion, theretaining lug being positioned level with the upper face of the lowerportion, and pliers comprising: an upper beak having a width andcomprising at least two blades, including a cutting blade that does notextend the full width of the upper beak so as to cut through the lugonly, and a crimping blade that extends the full width the upper beak.2. The combination according to claim 1, wherein the lower and upperfaces are serrated.
 3. The combination according to claim 1, wherein thecrimping blade is one of a plurality of crimping blades.
 4. Thecombination according to claim 1, wherein the pliers further comprise: alower beak comprising an upstand portion having a recess therein forreceiving the retaining lug, the retaining lug cooperating with therecess to prevent the retaining lug from being dislodged from therecess.
 5. The combination according to claim 4, wherein the lower beakof the pliers further comprises bore that extends vertically through theupstand from an outer face of the lower beak to the recess, the boreallowing insertion of an instrument to push the retaining lug out of therecess.
 6. A combination, comprising: safety attachment comprising: asafe-end portion comprising an upper portion having a lower face, alower portion having an upper face, and a hinge connecting the upper andlower portions to permit the lower and upper faces to be closedtogether, the safe-end portion having no sharp edges when lower andupper faces are closed together; and a retaining lug extending from thelower portion, the retaining lug being positioned level with the upperface of the lower portion, wherein the safety attachment furthercomprises: a wire retaining portion comprising an upper portion having alower face, a lower portion having an upper face, and a hinge connectingthe upper and lower portions to permit the lower and upper faces to beclosed together independently of the lower and upper faces of the upperand lower portions of the safe-end portion, and an isthmus connectingthe lower portion of the safe-end portion and the lower portion of thewire retaining portion, the isthmus being positioned level with theupper face of each of the lower portions.
 7. The combination accordingto claim 6, wherein the lower and upper faces are serrated.
 8. Thecombination according to claim 1, further comprising: pliers for saferemoval of the safe-end portion, the pliers comprising upper and lowerbeaks each including a cutting blade and a recess, the recess forreceiving and gripping the safe end portion as the blades cut.
 9. Acombination, comprising: a safety attachment, comprising: a safe-endportion comprising upper and lower portions that are connected by ahinge, a wire-retaining portion comprising upper and lower portions thatare connected by a hinge, and an isthmus between the safe-end portionand the wire-retaining portion and connecting the lower portions of thesafe-end portion and the wire-retaining portion; and first plierscomprising: an upper beak having three blades, comprising a first bladeto crimp the upper and lower portions of the wire-retaining portion sothat wire-retaining portion closes, a second blade, and a third blade tocrimp the upper and lower portions of the safe-end portion so that thesafe-end portion closes; and a lower beak, comprising a blade to fitunder the connecting isthmus, the blade of the lower beak being alignedwith the second blade of the upper beak, so that when the pliers areclosed, the isthmus is cut to separate the wire-retaining port and thesafe-end portion, the safe-end portion having no sharp edges when theisthmus is cut.
 10. The combination according to claim 9, wherein thesafety attachment further comprises: a retaining lug extending from thelower portion of the safe-end portion, and the pliers further comprises:an upstand portion on the lower beak, the upstand portion having arecess and an opening facing the blade of the lower beak, wherein therecess is shaped for receiving the retaining lug, the retaining lug andrecess cooperating to prevent the wire retaining portion from beingdislodged.
 11. The combination according to claim 10, wherein the lowerbeak of the pliers further comprises a bore that extends verticallythrough the upstand from an outer face of the lower beak to the recess,the bore allowing insertion of an instrument to push the retaining lugout of the recess.
 12. The combination according to claim 9, furthercomprising: second pliers comprising upper and lower beaks eachincluding a cutting blade and a recess, the recess for receiving andgripping the safe end portion as the blades cut.
 13. A combination,comprising: a safety attachment comprising: a safe-end portioncomprising upper and lower portions hinged together by a hinge, theupper portion having a lower face and the lower portion having an upperface, the upper and lower portions being hinged together to permit theupper and lower faces to close together, the safe-end portion having nosharp edges when lower and upper faces are closed together, and firstpliers comprising: an upper beak comprising at least two crimping bladesfor crimping the safe-end portion, and a lower beak comprising aprotrusion, running parallel to and between the two blades of the upperbeak, wherein the two blades and the protrusion therebetween deform thesafe-end portion.
 14. The combination according to claim 13, wherein thesafe-end further comprises a lower surface and an indentation in thelower surface, the protrusion and the indentation being shaped anddimensioned to provide an interference fit therebetween, whereby thesafe-end portion is retained on the pliers by friction between theprotrusion and the indentation.
 15. The combination according to claim14, wherein the interference fit is only provided in one direction. 16.The combination according to claim 13, further comprising: second plierscomprising upper and lower beaks each including a cutting blade and arecess, the recess for receiving and gripping the safe end portion asthe blades cut.
 17. A combination, comprising: a safety attachmentcomprising: a safe-end portion comprising upper and lower portionshinged together by a hinge, wherein the upper portion has a lower faceand the lower portion has an upper face, the upper and lower portionsbeing hinged together to permit the upper and lower faces to closetogether, the safe-end portion having no sharp edges when lower andupper faces are closed together, and first pliers comprising: an upperbeak comprising a central crimp blade, and a lower beak shaped withextensions and a central recess between the extensions to accept thesafe-end portion and support the safe-end portion while permittingdeformation of the safe-end portion when crimping the safe-end portion.18. The combination according to claim 17, wherein the safe-end portionfurther comprises an upper surface and a groove extending along theupper surface, the central crimp blade of the upper beak engaging thegroove.
 19. The combination according to claim 18, wherein the safe-endportion further comprises a lower surface and a ridge extending alongthe lower surface, wherein the groove and the ridge run substantiallyparallel to each other and substantially perpendicular to the hingejoining the upper and lower portions, the ridge assisting in retainingthe safe-end portion in the beaks of pliers.
 20. The combinationaccording to claim 17, further comprising: second pliers comprisingupper and lower beaks each including a cutting blade and a recess, therecess for receiving and gripping the safe end portion as the bladescut.